The present invention relates to devices, systems and methods for remotely detecting hazardous substances of a chemical or biological nature.
Spectroscopy is a useful technology for characterizing and/or identifying substances by analyzing the substance's response to application of certain types of light. One type of response that is useful is Raman scattering. Raman spectroscopy is a spectroscopic technique used to study vibrational, rotational, and other low-frequency modes in a system.
Fluorescence is another response useful to discern characteristics of a substance. Fluorescence refers to emission of light caused when a material absorbs optical energy of one wavelength and re-emits light of another wavelength. Fluorescence spectroscopy has evolved into a powerful tool for the study of chemical, semiconductor, photochemical, and biochemical species. Fluorescence lifetime is the average time that a molecule spends in the excited state before emitting a photon and returning to the ground state. Fluorescence lifetime is also an important and unique feature of an excited state.
It is desirable to provide a spectroscopy system and method that uses both Raman scattered energy and fluorescence scattered energy produced simultaneously in response to a beam of light in order to evaluate (characterize and/or identify) a substance.